Create the straight table. When you click on a bar in the bar chart the straight table will be filtered automatically too. If you don't want to show the straight table if no customer is selected then enable the option Conditional on the Layout tab of the properties window and enter an expression =getselectedcount(CustomerIDFieldHere). Replace CustomerIDFieldHere with the name of your customer field.
You can either set up your straight table (as a separate object, not in a container_box) with a visibility_condition and place it in the same position as your bar_chart and set the barchart with the opposite visibility_condition so when someone clicks on a bar (which you can find out with GETFIELDSELECTIONS()) the barchart will disappear and the details_table will appear - in that case, don't forget to implement sth. like a "Back" button to revert it ...
